Add serde derives to Pd, Pid and DynamicRaycastVehicle controllers (#883)

* Add serde derives to Pd, Pid and DynamicRaycastVehicle controllers

* Add Clone and Debug derives to DynamicRayCastVehicleController

Author: lokimckay

src/control/pid_controller.rs

@@ -10,6 +10,7 @@ use parry::math::AngVector;
 /// This is a [PID controller](https://en.wikipedia.org/wiki/Proportional%E2%80%93integral%E2%80%93derivative_controller)
 /// without the Integral part to keep the API immutable, while having a behaviour generally
 /// sufficient for games.
+#[cfg_attr(feature = "serde-serialize", derive(Serialize, Deserialize))]
 #[derive(Debug, Copy, Clone, PartialEq)]
 pub struct PdController {
     /// The Proportional gain applied to the instantaneous linear position errors.
@@ -51,6 +52,7 @@ impl Default for PdController {
 ///
 /// For video games, the Proportional-Derivative [`PdController`] is generally sufficient and
 /// offers an immutable API.
+#[cfg_attr(feature = "serde-serialize", derive(Serialize, Deserialize))]
 #[derive(Debug, Copy, Clone, PartialEq)]
 pub struct PidController {
     /// The Proportional-Derivative (PD) part of this PID controller.

src/control/ray_cast_vehicle_controller.rs

@@ -8,6 +8,8 @@ use crate::prelude::QueryPipelineMut;
 use crate::utils::{SimdCross, SimdDot};
 
 /// A character controller to simulate vehicles using ray-casting for the wheels.
+#[cfg_attr(feature = "serde-serialize", derive(Serialize, Deserialize))]
+#[derive(Clone, Debug)]
 pub struct DynamicRayCastVehicleController {
     wheels: Vec<Wheel>,
     forward_ws: Vec<Vector<Real>>,
@@ -23,6 +25,7 @@ pub struct DynamicRayCastVehicleController {
     pub index_forward_axis: usize,
 }
 
+#[cfg_attr(feature = "serde-serialize", derive(Serialize, Deserialize))]
 #[derive(Copy, Clone, Debug, PartialEq)]
 /// Parameters affecting the physical behavior of a wheel.
 pub struct WheelTuning {
@@ -101,6 +104,7 @@ struct WheelDesc {
     pub side_friction_stiffness: Real,
 }
 
+#[cfg_attr(feature = "serde-serialize", derive(Serialize, Deserialize))]
 #[derive(Copy, Clone, Debug, PartialEq)]
 /// A wheel attached to a vehicle.
 pub struct Wheel {
@@ -225,6 +229,7 @@ impl Wheel {
 
 /// Information about suspension and the ground obtained from the ray-casting
 /// to simulate a wheel’s suspension.
+#[cfg_attr(feature = "serde-serialize", derive(Serialize, Deserialize))]
 #[derive(Copy, Clone, Debug, PartialEq, Default)]
 pub struct RayCastInfo {
     /// The (world-space) contact normal between the wheel and the floor.